According to reports, Musk told staff that remote working would end and difficult times would follow.
Workers at the social media firm will be expected to work at least 40 hours a week according to an email sent to staff.
There was no way to sugar coat the message that the slowing global economy was going to hurt the company's advertising revenues.
The British Broadcasting Corporation has contacted the social networking site.
In June, Mr Musk told employees that working remotely was no longer acceptable.
A week after buying the company, the world's richest man announced that half of the staff would be let go.
The company was losing money and Mr Musk had no choice but to make the cuts. He blamedactivist groups for a drop in revenue.
Users will be able to buy blue-tick verified status for $8 per month as part of Mr Musk's shake-up of the social media platform.
Mr Musk told staff that he wanted half of the revenue to come from subscriptions.
There is concern that the platform could be swamped with fake accounts.
The verification badges were only given to notable or high-profile accounts.